The suspensory ligament is a centimeter thick structure that mostly consists of tendon tissue. In the forelimb, the suspensory ligament has its origin on the back side of the cannon bone (third metacarpal bone) immediately underneath the carpus, runs down along the cannon bone so as to, on a level with the fetlock of the horse, attach to the sesamoid bones of the fetlock and then branch off in lower lateral and medial branchings, which run on the respective side of the long pastern bone of the horse to be united in front to the long digital extensor tendon of the horse and attach on the dorsal side of the short pastern and coffin bone. The lower part of the suspensory ligament is the part that runs between the two lowermost attachments in the skeleton, from the proximal sesamoid bones and down to the final attachment in the short pastern/coffin bone. The purpose of the suspensory ligament is to carry and stabilize the fetlock and to work shock-absorbingly, and has to, in order to fulfil its purpose, be elastic. Upon loading of the fetlock, energy is stored in the suspensory ligament, which is released at the return of the fetlock from the loaded position.
A usual damage to the suspensory ligament is hyperextension, which regularly entails a long convalescence and healing time. Thus, there is a need of measures relieving the pressure on a damaged suspensory ligament and hastening the healing process.
A support for tendons and ligaments of horse is previously known from EP 1449497 B1. This device comprises a stiff upper collar shaped to surround the leg of the horse above the fetlock, and a stiff lower collar shaped to surround the leg underneath the fetlock. The collars are articulately connected via a swivel joint the axis of rotation of which should be arranged to coincide with the rotation of the fetlock. The object of the device is to limit the rotational ability of the fetlock. For this purpose, an elongate member is anchored in the two collars and arranged to extend between the collars on the back side of the leg. A central part of the solution is stated to be that said member should be non-elastic to its nature. The device is said to efficiently be able to replace tendons and ligaments and guarantee that all or essentially all downwardly directed force applied by the body mass during rest or training is transferred from tendons and ligaments to the front side of the leg.
It will be appreciated that the desired function imposes very high requirements of strength on the two collars and on the connection/joint between the collars, and that the material and construction costs therefore risk being high, as well as the weight of the device. It will also be appreciated that it is, in this solution, central that the collars and the connection joint always keep their exact location on the leg in order not for breaking forces to arise and counteract a natural movement in the fetlock/hoof.